212 AXNALS OF THE CaRNEGIE MuSEUM. 



these beds, some of which were described in his paper entitled " Types 

 of the Laramie Flora." He recognized several plant-bearing hori- 

 zons, all of which he included in the Fort Union formation, but he 

 considered the Fort Union as a part of the Laramie. It was hoped 

 that remains of mammalia, which would settle the status of these beds, 

 might be obtained. 



4. Mr. Douglass desired to search for fossils near Columbus in 

 Yellowstone County in Montana where he had previously found frag- 

 mentary remains of fossil reptiles. 



5. It was certain that large collections of invertebrates could be 

 secured from the various Palaeozoic, and probably from the Mesozoic 

 formations of western Montana, where Mr, Douglass had previously 

 collected. It was much to be desired that one more familiar with the 

 fossils and competent to judge of the relative importance of the differ- 

 ent faunae should visit the region in company with one who was 

 acquainted with the country. 



6. Most of the valleys of western Montana had been pretty thor- 

 oughly searched for Tertiary mammals, yet some quite large areas, 

 including the Flathead Valley, had not been explored for this purpose. 

 As nearly every locality and horizon from which fossil mammals had 

 been obtained had yielded much that was new and interesting, it was 

 important that all the localities should be carefully searched. 



7. It was surmised from reading accounts of explorations in Idaho 

 and from verbal reports that Tertiary beds, of the same age as some 

 of those which occur in Montana, extended into contiguous portions 

 of Idaho. This was made more probable by a knowledge of the fact 

 that in two places at least, one north of Henry's Lake in Idaho and 

 another south of the little railroad station of Monida in Montana, the 

 continental divide is comparatively low, and appears o be composed 

 of rocks of relatively modern date. 



All of the localities which it was proposed to explore were visited 

 by one or both of the members of the expedition, but circumstances 

 prevented anything like a thorough exploration of some of them. 

 Large collections of invertebrate fossils were obtained, many of which 

 are of unusual importance. Remains of fossil vertebrates were col- 

 lected in several localities, one or two of which had not been previ- 

 ously discovered, and many data of geological interest were obtained. 

 These data, combined with observations of former years, are given in 

 this paper Avith a hope that it will somewhat extend the geological 



